I personaly feel the 55 gallon is barly big enough to be a sump to a 280gallon tank..
but If thats what you plan on using it should work..
are you going to be using the sump as the primary filteration?
what type of filteration are you going to be using in the sump? natural or say wet/dry?
are you trying to get information as to the proper cycles per hour (I feel like that's debatable)?
or were you looking for recomended pumps for you setup or just brands?
sorry your question seemed a little vague to me.